exam 2 ch 13 Flashcards
The branch of evolutionary biology that studies the diversity of reproductive
strategies
life-history analysis
Have a high growth rate but low survivability (“cheap” offspring)
r-selected species
Have a low growth rate but high survivability (“expensive” offspring)
K-selected species
Changes in life history are caused by changes in the?
allocation of energy
Number of gametes produced by an individual
Fecundity
selection will favor the number of offspring that results in the most surviving
offspring
Lack’s Hypothesis
individual offspring survival decreases with increasing offspring number
Trade-off
Energy contained in the offspring themselves
Direct costs
Energy expended to produce and carry them
indirect costs
- (a) There is a trade-off between size and number of offspring.
- (b) Above a minimum size, the probability that any individual offspring will survive is an increasing
function of its size
Selection on Offspring Size
Assumptions
selection on Offspring Size
-Selection on parents favors a compromise
between the quality and quantity of offspring,
-Selection on individual offspring favors
high quality
Fertilization of two or more ova from the same cycle by sperm from separate
acts of sexual intercourse
Superfecundation
Only one copy of a gene in an individual (from mother or father) is expressed,
while the other copy is suppressed
Genomic imprinting
A growth promoting hormone.
Insulin-like growth factor II
A receptor that binds IGF-II to promote
lysosome activity
Cation-independent mannose-6-phosphate receptor (CI-MPR)
When mates are not monogamous, the life-history strategy that is ___________________________ for the other
optimal for one sex may be
suboptimal
Life-history traits have ________________________ than other traits.
lower heritabilities
Low heritability means traits are more influenced by?
environmental factors
Higher reproductive capacity allowed dinosaurs to?
recover more quickly from population bottlenecks
Describes the molecular changes seen in most aging cells
The Hallmarks of Aging
There are 2 main models of aging;
- Damaged-based model
- Programmatic models
- Damaged-based model
(Damage to DNA and cells accumulates)
- Programmatic models
(Aging is encoded in the DNA)
Mammals with higher somatic mutation rates have ______ lifespans
shorter
non-sex cells
somatic cells
are highly reactive chemicals formed from diatomic oxygen (O2),
water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (-OOH), superoxide (O2-),
hydroxyl radical (OH.)
Reactive oxygen species (ROS)
During DNA replication, at the end of the lagging the final RNA primer is
removed leaving a small site that is not replicated by polymerase, meaning that there will be a small
amount of DNA lost each time the cell divides.
End replication problem
A region of repetitive DNA sequences that protect the ends of chromosomes
Telomeres
As cells divide, the telomere ends of chromosomes get shorter
Telomere attrition
The limit on cell replication imposed by the shortening of telomeres with each
division.
Hayflick limit
A reverse transcriptase that adds repeats of a DNA sequence to the ends of
chromosomes.
Telomerase
There are 2 main models of aging?
- Damaged-based model
- Programmatic models
-Conserved methylation sites were highly enriched in polycomb repressive complex 2-binding locations, which
represses the transcription of diverse developmental genes
Aging Clocks
Methylation clocks indicate aging has a predictable?
preset program
Age at which RNA expression pattern reverses direction
transcriptome Trajectory Turning Points (TTTP):
- Damaged-based model
(Damage to DNA and cells accumulates)
- Programmatic models
(Aging is encoded in the DNA)
Peak at ~age 26 =?
End of brain development = same time as onset of aging phenotypes
Adult cells reprogrammed back into an embryonic-like
pluripotent state that enables them to become any type of cell.
induced Pluripotent Stem Cells (iPSC’s)
The transcription factors (Oct4 (Pou5f1), Sox2, Klf4 and cMyc) that were used to turn adult cells
into Pluripotent stem cells
yamanaka Factors
